It has been conventionally proposed to exhaustively detect or quantitate nucleic acid sequences in order to carry out genetic analyses of individual organisms and to test an infection of biological samples with viruses or bacteria. For example, microarrays (hereinafter merely referred to as “arrays”) are used for detecting an expression level of nucleic acid sequences to be detected (target nucleic acids) in samples (e.g., see Non-patent documents 1 to 4) Arrays are carriers on which multiple nucleic acid fragments (detection probes) having known base sequences are independently fixed. As shown in FIG. 8, in conventional array methods, a forward primer (F primer) and a reverse primer (R primer) designed so as to flank the target sequence are used to amplify a DNA fragment (target nucleic acid) containing the target sequence. The amplified nucleic acid is then separated to a single strand. The target nucleic acid then binds on the carrier by hybridization of the target sequence with a portion complementary to a partial sequence characteristic to the target nucleic acid (target sequence). The hybridized target nucleic acid is detected by any suitable method to determine a presence or absence of the nucleic acid in the sample. Arrays specific for detection of single nucleotide polymorphisms (SNPs) have been developed (e.g., see Patent documents 1 and 2). By this method, a type of SNPs of the target nucleic acid in the sample can be detected by using DNA computer technology.